Resonant amplifying-receiver.



A. e. KEPLINGER. RESONANT AMPLIF YING RECEIVER.

APPLICATION FILEIYNOV. 14.1914.

1 ,1 85,680. PatentedJune 6, 1916.

INVENTOR ARTHUR G. KEPLINGER, OF KANSAS CITY, ILANSAS.

RESONANT d'MPLIFYING-RECEIVEE.

aaeeo.

Specification of Letters Patent.

Application filed November 14, 1914. Serial No. 872,111.

To all whom it may concern:

Be it known that I, ARTHUR G. KEPLIN- GER, a citizen of the United States, residing at Kansas City, in the county of \Vyandotte and State of Kansas, have invented certain new and useful Improvements in Resonant Amplifying-Receivers, of Which the follow ing is a specification.

This invention relates to radio telegraph apparatus and more especially to a receiver therefor, my object being to produce a receiver having resonant and amplifying properties.

Another object is to produce a receiver having a resonant and amplifying chamber which can be increased or diminished in length.

The advantages of a receiver possessing a resonant and sound amplifying chamber are as follows: It permits of increasing the audibility of faintly received signals to'permit communication to take place where it has been impossible heretofore; it aids in making the signals from a given station have preponderance over others and thereby. increases selectivity; and it tends to overcome static'disturbances and other annoyances such as occur from induced currents from neighboring power lines and the like, I

by amplifying the received signals only.

With these objects in View. the invention peculiar features of construction, andorganization as hereinafter described and particularly pointed out in the claims, and in order that it may be fully understood reference is to be had to the accompanying drawing, in which-- Figlire 1, is a central vertical section of a receiver embodying-my invention. Fig. 2, is an elevation of the receii'er partly broken away to more clearly disclose the arrangement of the internal mechanism thereof. Fig. 3, is a front view of the receiver with the ear cap and diaphragm omitted.

in detail, 1 indicates a tube open at both ends and provided at its front end with an external thread 2, and at its rear end with flaring mouth 3. Fitting, telescopically on tube 1, is a tube 4, which is closed at its 2' end to form reflecting head 5. Elle tubes together constitute a holiow body or resonant chamber, closed at its rear end and za'iglustable as to length, and both tubes are 6 is an ear cap screwed upon the front end of the hollow body and provided with a central perforation or opening 7, and clamped against the front end of the hollow body by said cap and spaced from the lat ter for the greater portion of its area, is a diaphragm S.

9 is a circular permanent magnet externally embracing the tube 1 adjacent the open end of the same andbolted or otherwise ;secured to said tube as at 10. The permanent magnet does not completely encircle the tube, and secured to its extremities is a pair of arms 11 which extend through the wall and into the chamber of tube 1, and terminate in forwardly projecting polepieces 12 which are spaced slightly rearward of the central portion of the diaphragm 8.

15 is a pair of electro-magnets mounted upon said pole pieces and wired in the cus tomary manner to each other and to terminals 14 secured in the wall of the tube, wires 15 of a circuit common in wireless telegraphy, being attached to the terminals 14-.

. It will be noted that by locating the per-- manent magnet on the exterior of the hollow body and disposing the arms 11 and their pole pieces 12, edgewise to the direction in which the Bound waves traverse the resonant chamber, no material impediment to the travel of the sound waves within said chamber is bfiered. The electro-magnets do not seriously interfere with the travel of such Waves because of their small size and. central location and the provision of a liaring mouth for the rear end of the tube 1, avoids resistance to the waves reflected by the head which would be present if the rear end of said tube presented an abrupt rear- 0 energization of the magnets wili produce within the resonant chamber sound waves which will travel rearwardly nntii they im pinge upon and are reflected back by the refleeting head 5. This reflection of the sound waves causes themto strike the diaphragm and cooperate in the vibration of the same by the magnet. By this means the vibration. of the diaphragm. is increased or amplified Patented June 6, .1916 i snfiiciently to produce signals clearly audible to the operator against Whose ear the ear cap rests. v

From the above description it will be apparent that I have produced a receiver for rediotelegraph systems embodying the features of advantage enumerated as desirable, and I wish it to be understood that while have illustrated and described the preferred embodiment of the same, I reserve the right to make all changes falling within the, spirit and scope of the appended claim;

I claim:

In a receiver for radio telegraph systems,

at resonant chamber, comprising a.- smooth open tube having a flaring mouth at its rear end a tube smooth internally, fitting slidingly on the open tube and hzwing a; closed rear end forming a, reflecting head for diineseeo resting sound waves forwardly into the firstnamed tube through the flaring mouth thereof, a perforated ca secured on the front end of the first-name tube, a diaphragm secured at the front end of the slightly heck of and spaced from the per Jforeted portion of the cap, eleetro-magnets located within the resonant chamber close to the central portion of the diaphragm, and conductors connecting and lending to'and from said eleotro-magnets whereby the same may be periodically energized lay-pulsations of current.

In testimony whereof, 1 afiix my signw ture, in the presence of two Witnesses.

ARTHUR G. KEPLINGER. Witnesses RODGERS, G. Y. Timers.

I said tube 

